Willian dispatched Newcastle with a winner worthy of a better game and then outlined why he intended to stay at Chelsea in spite of interest from Barcelona.

The Brazil winger is now in the 30-and-over bracket, which means a contract that has 18 months to run would be only moderately extended under current club policy.

Willian made it clear, however, that he would prefer that to a switch to Barcelona.

"Yeah, I have seen that, but my future is here," he said of the Barcelona link. "I want to stay until my contract is finished. My head is here. My focus is here.

"Would I like a new contract? Of course. I am very happy. So, if they want me to sign, of course I want that. Chelsea is a great team."

A 2-1 victory that left Newcastle in the bottom three gave Chelsea a six-point cushion ahead of fifth-placed Arsenal, yet it was obvious that everything is far from rosy in the garden being cultivated by Maurizio Sarri.

The Italian has constantly talked of the need to improve the "mentality" of players who have developed a habit of fading alarmingly for no discernible reason, and they did so again in this game.

Pedro gave Chelsea a ninth-minute lead with a lofted finish from David Luiz's long ball over the top of a five-man midfield.

However, with Eden Hazard anonymous in the 'false-nine' role he does not like, Newcastle deservedly levelled before half-time through Ciaran Clark's brilliant header from a corner.

In the only portion of the game when Hazard did look lively, the Belgian set up Willian for a curled finish just before the hour mark that turned out to be just enough to seal a laboured victory.

Sarri admitted Hazard had not looked like he was enjoying himself in the first half, but argued that the team were "more balanced" with him in the central striking role instead of Olivier Giroud, who replaced him for the final three minutes, or Alvaro Morata, who was left out of the squad.

Coaxing on-loan Juventus striker Gonzalo Higuain away from AC Milan would allow Hazard to move into his favoured position on the left, and Sarri is also crossing his fingers that deals for midfielders Nicolo Barella of Cagliari or Zenit St Petersburg's Leandro Paredes can be sealed sooner rather than later.

Cesc Fabregas's departure to Monaco left only 18-year-old Ethan Ampadu on the bench as a central-midfield option should Jorginho suddenly start misfiring, which he did after just 20 minutes against the Magpies.

"Maybe he was tired, I don't know. "But if Fabregas was on the bench in the second half, he would have been on the pitch instead of Jorginho," said Sarri, who chose not to use Ampadu.

Then there is the Callum Hudson-Odoi conundrum. Sarri sent on the 18-year-old for the final nine minutes and the Bayern Munich target was serenaded by the home fans.